Some reports saying that it is more expensive to live in Shanghai and Beijing than in New York are misleading, said economics professor of Shanghai Party Institute, Wang Zhiping.

Wang said human resource service provider Mercer's "cost of living" is for expatriate employees, not for average residents. Wang added that mixing up these two types of "cost of living" does no good for scientific comparison and may result in emotional reactions.

Hong Kong ranks 9th globally in cost of living and Shanghai and Beijing ranks 16th and 17th respectively while New York ranks 33rd, according to Mercer's 2012 Cost of Living Survey city rankings published on June 12.

Wang said that expatriates' housing costs are obviously higher than average residents as they live in the downtown, which partly explains why Shanghai and Beijing's rankings are ahead of New York.

The survey covers 214 cities across five continents and measures the comparative cost of over 200 items in each location, including transport, food, clothing, household goods and entertainment, according to Mercer's website. It is designed to help multinational companies and governments determine compensation allowances for their expatriate employees.